The equation of a wave travelling on a string is $\mathrm{y}=\sin [20 \pi \mathrm{x}+10 \pi \mathrm{t}]$,…
The equation of a wave travelling on a string is $\mathrm{y}=\sin [20 \pi \mathrm{x}+10 \pi \mathrm{t}]$, where x and t are distance and time in SI units. The minimum distance between two points having the same oscillating speed is :
5.0 cm
20 cm
10 cm
2.5 cm
Solution
Minimum distance between 2 points having same speed is $\frac{\lambda}{2}$. $\lambda=\frac{2 \pi}{\mathrm{k}}=\frac{1}{10} \mathrm{~m}=10 \mathrm{~cm}$ $\text { Distance }=\frac{\lambda}{2}=5 \mathrm{~cm}$